Many types of weather-resistant sheet materials are available for use in the building construction industry. For example, webbed sheets including tar paper and spun-bonded polyolefin house wraps are available for use as an underlayment under shingles or siding or facers for foamed insulation board laminates. In the past, webbed sheets have been made with cellulostic felt or Kraft paper which has been treated with either coal tar pitch, asphalt, or pine rosin. However, such cellulostic products typically lose their desired flatness upon contact with water, organic liquid, or other types of moisture. Similar cellulostic products are flammable and can therefore constitute fire safety hazards.
Glass fiber mats made of non-woven glass fibers can be used in place of the cellulose sheets as the facer material in laminates. In comparison with cellulose products, glass fiber mats can provide improved resistance to liquid penetration. Glass fiber mats can also maintain their shape and form upon contact with liquids and provide improved flame retardant characteristics in comparison with cellulose products.
A conventional glass fiber mat-containing laminate or composite board can have an inner layer of material set between two, outer layers of glass fiber mats. The outer surface of each glass fiber mat can be coated with a coating material to reduce porosity and increase resistance to liquid penetration. The inner surface of each glass fiber mat remains uncoated and is directly attached to the inner layer material.
Conventional glass fiber mat-containing laminate or composite boards typically exhibit undesirable characteristics such as, for example, insufficient mechanical strength, which can cause problems during the installation, use and/or maintenance of the products. For example, in roofing underlayment applications, the laminate or composite board is attached to a roofing membrane. When the roofing membrane is peeled away from the laminate/composite board, for example, to conduct maintenance on the roof, portions of the laminate/composite board can tear away with the roofing membrane due to the insufficient mechanical strength thereof. Additionally, conventional laminate/composite boards are typically susceptible to deterioration when used in high-pH applications, such as tile backing. A further disadvantage of employing conventional laminate/composite boards is that when the glass fiber mat is adhered to an insulating foam during manufacture, the surface intended to be adhered to the foam typically consumes insulating foam, thereby increasing manufacturing time and consumption of materials.